Toothbrush Head

ABSTRACT

A toothbrush head with a bristle support member on which a bristle zone with a plurality of bristle tufts is arranged. The bristle tufts include three differently inclined groups of bristle tufts of which a first group is arranged essentially perpendicular to the plane of the bristle support member, a second group is inclined in a direction transverse to the toothbrush head longitudinal axis towards a first side, and a third group is inclined in a direction transverse to the toothbrush head longitudinal axis towards an opposite second side, with the inclined bristle tufts of the second and third group being arranged in transverse rows on the bristle support member. In each transverse row of inclined bristle tufts, all the bristle tufts are inclined towards the same side, with the bristle inclined from the outside inwards.

TECHNICAL FIELD

This invention relates to a toothbrush head, more particularly to atoothbrush head with three differently inclined groups of bristle tufts.

BACKGROUND

Manual toothbrushes have, in their simplest version, bristle tufts whichare oriented on the bristle support member to be perpendicular to theplane defined by the support member. There are many differentmodifications of this arrangement in existence. They include brush headswith tufts of various length, cf. U.S. Pat. No. 6,276,021 or U.S. Pat.No. 5,305,489, brush heads with tufts with variously long bristles, cf.WO 98/07348, brush heads with bristle tufts inclined in the direction ofthe toothbrush longitudinal axis, cf. U.S. Pat. No. 6,272,714, andtoothbrush heads with bristle tufts inclined in a direction transverseto the toothbrush longitudinal axis. The latter arrangement, disclosedin U.S. Pat. No. 5,335,389, has a plurality of bristle tufts arranged intransverse rows one behind the other on the bristle support member. Inthis arrangement, transverse rows with non-inclined bristle tuftsalternate with transverse rows which have inclined bristle tufts. Assuch, the outermost bristle tufts in a transverse row are inclinedoutwards so that they are splayed apart in V-shape. The outer, outwardlyinclined bristle tufts are intended to clean simultaneously the gingivalspace at the gingival margin of the upper jaw and at the gingival marginof the lower jaw.

A similar arrangement of bristle zones with outwardly inclined bristletufts at the outer edge of the bristle zone is disclosed in U.S. Pat.No. 5,628,082, U.S. Pat. No. 3,722,020, U.S. Pat. No. 4,010,509 or WO2004/037038 A1. The latter document discloses, in addition to thetransverse rows of bristle tufts with outwardly inclined bristle tufts,a transverse row with two inwardly inclined bristle tufts. With the aidof these counter-inclined bristle tufts it should be possible to achievein particular an improved cleaning of the concave biting surface of themolars. However, such counter-inclined bristle tufts are less suited forcleansing in the interproximal area and in the gingival area of theteeth. The ends of the counter-inclined bristle tufts are no longer ableto move freely in their predetermined incline and are obstructed by theother bristle tufts with the opposite incline.

A bristle zone with inwardly inclined bristle tufts is also disclosed inWO 01/89344 A2, in which the bristle tufts are inclined not only in adirection transverse to the toothbrush longitudinal axis but also in thedirection of the toothbrush longitudinal axis. With this configuration,the bristle tufts of a transverse row are inclined in differenttransverse and longitudinal directions so that the bristle tufts partlyoverlap when looking in both the toothbrush longitudinal direction andthe toothbrush transverse direction. Here too the result is anobstruction of the inclined bristle tufts by bristle tufts with adifferent inclination. With this toothbrush, the cleaning of the planarportions of the teeth is capable of improvement in addition.

Furthermore, CH 324623 discloses a toothbrush with transverse rows ofbristle tufts each inclined in one direction. This toothbrush sets outto do completely without perpendicular bristle tufts in order not togrind any flutes in the dental enamel and in order to preventwedge-shaped defects there in the long term. With this prior knownbristle configuration it is possible to achieve a satisfactory cleansingof the interproximal spaces, but the cleansing of the planar areas ofthe teeth is poor.

SUMMARY

In one aspect, a toothbrush head includes a bristle support member onwhich a bristle zone with a plurality of bristle tufts is arranged.Three groups of bristle tufts are arranged on the bristle zone andinclined in special manner. The bristle tufts of the second and thirdgroup, which are provided in addition to the perpendicularly arrangedbristle tufts of the first group, are inclined from the outside inwards,whereby in each transverse row of inclined bristle tufts all the bristletufts of a transverse row are inclined towards the same side. The termfrom the outside inwards as used herein means an arrangement in which,when a transverse row is considered in its entirety, the bristle tuftbase lying on the bristle support member lies closer to the outer edgeof the bristle zone than the bristle tuft head which, when a transverserow is considered in its entirety, lies more in the center of thebristle zone. If a bristle tuft lies with its tuft base on the left-handside of the bristle support member, then it is inclined from the outsideinwards when its free end is inclined towards the right-hand side of thebristle support member.

Through the triple oriented groups of bristle tufts it is possible,without special tilting of the toothbrush head, to cleanse both theplanar portions of the teeth as well as the interproximal and gingivalareas of the teeth equally effectively. The perpendicularly upstandingbristle tufts of the first group ensure a thorough cleansing of theplanar portions of the teeth. By contrast, the inclined bristle tufts ofthe second and third group clean the interproximal and gingival areas ofthe teeth. The special arrangement of the inclined bristle tufts, namelythe inclination of all the bristle tufts in the same transverse row tothe same side, namely from the outside inwards, has the effect that allthe ends of the bristle tufts of the second group, which are inclinedfor example from left to right, point in the direction of the gingivalmargin and clean there when the toothbrush is engaged against a jawhalf. At the same time, all the ends of the bristle tufts of the thirdgroup, which then are inclined in reverse from right to left, then pointin the direction of the occlusal surfaces of the teeth, enabling them topenetrate into the interproximal area of the teeth. Using a simplecleaning movement parallel to the row of teeth, this results in asimultaneous cleaning of different areas, namely the middle planarportions of the teeth, the gingival area and the interproximal area ofthe teeth, without the toothbrush needing to be specially tilted. Thetoothbrush head described herein, when placed untilted on a jaw half,unites in this case the technique referred to as the Bass technique,with which the toothbrush is placed such that the bristle ends areinclined towards the gingival area of the teeth, and the techniquereferred to as the Charters technique, with which the toothbrush isplaced such that the bristle tufts are oriented away from the gingivalmargin towards the occlusal area of the teeth. If the toothbrush head isengaged parallel to the row of teeth against the facial or lingual toothsurfaces, then the bristle ends of the inclined bristle tufts alignthemselves along the tooth axis. The bristle tufts of the one directionof inclination move towards the gingival margin while the bristle tuftsoriented in the opposite direction move towards the masticatorysurfaces. Because of the dimensions and arrangement of the tufts, thebristle ends of the bristle tufts of one direction of inclination end inthe area of the gingival margin while the bristle ends of the bristletufts inclined in the other direction reach, when placed in position,into the interproximal area in particular because as the result of theproposed arrangement they are not obstructed by any other bristle tufts.The bristles of the perpendicularly upstanding bristle tufts end on thefacial or lingual surfaces. In consequence, the toothbrush must nolonger be moved successively into different defined positions in orderto clean the different areas of the teeth. An effective cleaning of thedifferent areas takes place concurrently even during a simple movementalong the row of teeth referred to as the horizontal scrubbingtechnique.

In this arrangement, the bristle tufts of the inclined transverse rowsmay be inclined solely in a direction transverse to the toothbrushlongitudinal axis so that they extend in a plane perpendicular to thetoothbrush longitudinal axis. In this way the above described effect ofcleaning the interproximal area and gingival area of the teeth can beachieved in excellent manner.

In some implementations, the bristle tufts of the second and/or thirdgroup may also have, in addition to their inclination transverse to thetoothbrush longitudinal axis, an inclination component in the directionof the toothbrush longitudinal axis. Through a slight inclination alsoin the direction of the toothbrush longitudinal axis it is possible toimprove the penetration of the correspondingly inclined bristle tuftsinto the interproximal spaces in particular during horizontal scrubbing.With this configuration, forwardly inclined tufts penetrate into theinterproximal spaces when the brush is pushed forward. Backwardlyinclined tufts penetrate into the interproximal spaces when the brush ispulled backward.

There is no need in general for the bristle tufts arranged in atransverse row to have the same inclination. For example, bristle tuftswhich are anchored farther to the outside on the bristle support membercould exhibit a stronger inward inclination than bristle tufts which arearranged farther inside on the bristle support member. However, in someimplementations, all the bristle tufts arranged in a common transverserow are of like inclination. This promotes a uniform cleaning effect ofa respective transverse row of inclined bristle tufts.

Provided they are arranged respectively in a common transverse row, thenin particular the bristle tufts of the second and third group arearranged in a common plane which otherwise has no differently inclinedbristles or perpendicularly upstanding bristles. The bristle tuftsarranged in a common plane are all inclined to the same side and are notobstructed by differently inclined or perpendicularly upstanding bristletufts. In this way a collision between differently inclined bristletufts is ruled out. Penetration into the interproximal area of the teethon the one hand and cleaning of the gingival area of the teeth on theother are thus rendered still more efficient.

In principle it would be conceivable for the bristle ends of thedifferent groups of bristle tufts to lie in a common plane. However, insome implementations, the bristle tufts of the second and/or third groupare constructed to be higher than the bristle tufts of the first group.In this way the inclined bristle tufts are better able to penetrate intothe interproximal or subgingival area, while at the same time theperpendicularly upstanding bristle tufts stand upright on the planarsurfaces of the teeth for cleaning this particular area.

In this configuration, it would be conceivable in principle for thebristles within the same group of bristle tufts to end in a commonplane. Preferably, however, the bristles of the different bristle tuftsof the second group as well as the bristle tufts of the third group endat different levels. In particular the bristle tufts in a commontransverse row are constructed to be different in height. As such,preferably the inclined bristle tufts, whose head lies approximately inthe center of the bristle zone, are constructed to be higher than theinclined bristle tufts of the same transverse row which are arrangedwith their head farther outside towards the edge of the bristle zone. Inthis way there results, looking in the longitudinal direction of thetoothbrush head, an approximately roof-shaped envelope contour which isdefined by the ends of the inclined bristle tufts.

Preferably, the heads of the inclined bristle tufts in a commontransverse row form an approximately rectilinear contour downwardlysloping towards the outer side of the bristle zone. Said rectilinearcontours, which are described by the heads of the inclined bristletufts, are downwardly sloping in counter-inclined transverse rowstowards opposite sides so that on the whole the previously mentionedapproximately roof-shaped contour results in the toothbrush longitudinaldirection looking at the bristle zone.

Advantageously, the counter-inclined bristle tufts of the second groupand the third group are arranged such that, looking in the toothbrushlongitudinal direction, the bristle tufts of the second group overlap atleast partly the bristle tufts of the third group and vice versa.Advantageously, the arrangement is chosen such that each bristle tuft ofthe second group, looking in the toothbrush longitudinal direction,overlaps at least one bristle tuft of the third group and vice versa.

In some implementations, the bristle zone has in its head or workingarea a greater bristle tuft density than in the foot zone on the bristlesupport member. The base area of the bristle zone, which is defined bythe bristle tuft feet on the bristle support member, is at least aslarge as the working area of the bristle zone defined by the bristletuft heads. Owing to the inclination of the bristle tufts of the secondand third group from the outside inwards, an expansion of the bristlezone with the height of the bristles increasing is prevented fromoccurring.

In some embodiments, the bristle zone encompasses at least threetransverse rows of bristle tufts of the second group as well as at leastthree transverse rows of bristle tufts of the third group. Preferably,in this configuration the transverse rows of the bristle tufts of thesecond group and the transverse rows of the bristle tufts of the thirdgroup are arranged alternately one behind the other in the toothbrushlongitudinal direction. The perpendicularly arranged bristle tufts ofthe first group are arranged advantageously between the transverse rowsof the second and third group.

In particular a pair of transverse rows of bristle tufts of the secondgroup and bristle tufts of the third group are followed in thetoothbrush longitudinal direction by bristle tufts of the first groupbefore there again follows a pair of transverse rows of bristle tufts ofthe second and third group.

By arranging the inclined bristle tufts of the second and third group inplanes perpendicular to the toothbrush head longitudinal axis, thebristle tufts of the first group may be arranged likewise in transverserows perpendicular to the toothbrush longitudinal axis. However, if thebristle tufts of the second and third group are biaxial, i.e., arrangedboth transverse to the toothbrush longitudinal axis and parallelthereto, inclined and/or arranged in planes which are inclined at anacute angle to the toothbrush longitudinal axis, then the bristle tuftsof the first group may be combined to form triangular bristle zonesections between respective transverse rows of inclined bristle tufts.

The bristle tufts of the three groups generally may have the samecross-section, with different cross-sectional shapes being possible. Forexample, the bristle tufts may have a round, an angular or an elongatedcross-section. In some cases, provision may be made for theperpendicularly upstanding bristle tufts of the first group to have across-section which differs from the cross-section of the bristle tuftsof the second and third group. In particular the bristle tufts of thefirst group may have an essentially approximately circularcross-section. By contrast, in certain cases, the bristle tufts of thesecond and third group may have an approximately rectangularcross-section, with the cross-section extending with its longitudinalsides parallel to the outer contour of the respective transverse row inwhich the respective bristle tuft is arranged.

The degree of inclination of the bristle tufts of the second and thirdgroup may generally be selected to differ. According to a preferredembodiment, the bristle tufts of the second and third group are inclinedrelative to a perpendicular on the bristle support plane at an angle of5° to 45°, preferably 15° to 30°, approximately. In particular thebristle tufts may be inclined relative to the perpendicular on thebristle support plane at an angle of 20° to 25°, approximately.

These and further features which, in combination and sub-combination,may form the subject matter of the present description will becomeapparent not only from the claims but also from the subsequentdescription and the associated drawing with reference to which preferredembodiments are be explained.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a toothbrush head of a manual toothbrushhaving a bristle zone;

FIG. 2 is a perspective view of a toothbrush head of a manualtoothbrush;

FIG. 3 is an end view of the toothbrush head of FIG. 2;

FIG. 4 is a side view of toothbrush head of FIGS. 2 and 3; and

FIG. 5 is a top plan view of the bristle zone of the toothbrush head ofthe preceding FIGS. 2 to 4.

DETAILED DESCRIPTION

The toothbrush heads 1 illustrated in the drawings have an approximatelyplate-shaped bristle support member 2 to which a plurality of bristletufts are attached, which combine to form a bristle zone 3. The bristletufts may be attached to the bristle support member 2 in a variety ofways. For example, they may be anchored on the bristle support member 2by an anchor tufting method or they may be integrally molded in thebristle support member 2 by an injection molding method or be fastenedto the bristle support member 2 by a welding method.

The bristle tufts are divided into three different groups of bristletufts. A first group of bristle tufts 4 is arranged essentiallyperpendicular to the plane defined by the plate-shaped bristle supportmember 2. A second group of bristle tufts 5 is inclined in a directiontransverse to the toothbrush head longitudinal axis 7 towards a firstside of the toothbrush head, while the third group of bristle tufts 6 isequally inclined in a direction transverse to the toothbrush headlongitudinal axis 7 but towards the opposite side of the toothbrushhead.

In the embodiment of the toothbrush head 1 shown in FIG. 1, the bristletufts are arranged in transverse rows on the bristle support member 2.As FIG. 1 shows, the perpendicularly arranged bristle tufts 4 of thefirst group are arranged in altogether five transverse rows on thebristle support member 2, each transverse row accommodating between twoand four bristle tufts 4. Arranged between the respective transverserows of the bristle tufts 4 of the first group is one transverse row ofbristle tufts of the second group and one transverse row of bristletufts 6 of the third group so that on the whole transverse rows ofbristle tufts from the first group, the second group and the third groupalternate with each other.

The bristle tufts 5 of the second group, which are arranged in a commontransverse row, lie in a common plane which extends essentiallyperpendicular to the longitudinal axis 7 of the toothbrush head 1. Inthis arrangement, all the bristle tufts 5 of the second group have thesame angle of inclination towards the same side. Similarly, the bristletufts 6 of the third group, which are arranged in a common transverserow, have the same angle of inclination towards the opposite side, beingarranged in a common plane. The angle of inclination 8 of the bristletufts 5 of the second group amounts preferably to approximately 85 to55° relative to the plane defined by the bristle support member 2 (cfFIG. 1). The angle of inclination of the bristle tufts 6 of the thirdgroup is equally large but oriented towards the opposite side of thetoothbrush head 1.

In the embodiment shown in FIGS. 2 to 5, the inclined bristle tufts 5 ofthe second group and the inclined bristle tufts 6 of the third group arelikewise combined in transverse rows.

In the embodiment of FIGS. 2 to 5, the bristle tufts 5 of the secondgroup as well as the bristle tufts 6 of the third group have aninclination both transverse to the toothbrush longitudinal axis 7 andparallel thereto. As shown in particular in FIG. 5, the bristle tufts 5and 6 are arranged in transverse rows which do not extend at rightangles in a direction transverse to the longitudinal axis 7 but slightlyobliquely in a direction transverse to the longitudinal axis 7. In theembodiment shown (cf. FIG. 5), the transverse rows adopt an angle of 40°to 60°, approximately, relative to the longitudinal axis 7. The bristletufts 5 and 6, which are attached to the bristle support member 2 in onetransverse row each, are oriented such that they extend in a commonplane and have the same inclination in said plane, as shown in FIG. 3.It will be understood, of course, that here too the bristle tufts 5 ofthe second group are inclined towards the one side of the bristlesupport member 2 while the bristle tufts 6 of the third group areinclined towards the other side of the bristle support member 2. In theembodiment shown, provision is made for respectively two bristle tufts 5of the second group and two bristle tufts 6 of the third group pertransverse row. The angle of inclination of said bristle tufts 5 and 6of the second and third group, respectively, relative to theperpendicular 9 on the bristle support plane amounts in the embodimentshown to 20°, approximately. As FIG. 3 shows, the bristle tufts 5 and 6of the second and third group are inclined from the outside inwards alsoin the embodiment of FIGS. 2 to 5. The base of the bristle tufts 5 and 6attached to the bristle support member 2 is offset—when looking at atransverse row in its entirety—to a side edge of the bristle zone 3,with the respective bristle tufts 5 and 6 then extending with their tipsto the other side of the bristle zone 3 and hence inwards.

As FIG. 3 shows, the inclined bristle tufts 5 and 6 do not all have thesame length or height. The arrangement is chosen such that the bristletufts 5 a and 6 a lying with their head in the center of the bristlezone 3 have a greater height than the bristle tufts 5 b and 6 b lyingwith their head farther to the outside. In this configuration, the freeends of the bristle tufts 5 and 6 are coordinated with each other inheight such that the bristle tufts 5 and 6 arranged in the sametransverse row define with their heads a rectilinear contour whichslopes downwards to the outer side of the bristle zone 3 (cf. FIG. 3).As such, the ends of the bristle tufts 5 and 6 tilted to different sidesdefine contours downwardly sloping to opposite sides so that angable-roof-shaped envelope contour is defined by the ends of theinclined bristle tufts 5 and 6 (cf. FIG. 3).

As FIGS. 2 and 4 show, in this second embodiment the inclined bristletufts 5 and 6 are again not obstructed from bending to and fro in theirplane of inclination by other bristle tufts that are arrangedperpendicular or are otherwise inclined. In each transverse row oftilted bristle tufts 5 or 6 there are only bristle tufts of the sameinclination. In the planes that are defined by the bristle tufts of atransverse row, the bristle zone 3 is constructed devoid of otherbristles.

Arranged between the transverse rows of inclined bristle tufts 5 and 6are the bristle tufts 4 of the first group which are perpendicular tothe plane of the bristle support member 2. As FIGS. 2 and 5 show, thebristle tufts 4 of the first group are arranged in triangular bristletuft zones between the rows of the inclined bristle tufts 5 and 6 sothat after a zone of bristle tufts 4 of the first group there follows,looking in the longitudinal direction of the toothbrush head 1, onetransverse row of bristle tufts 5 of the second group and then onetransverse row of bristle tufts 6 of the third group, this sequencebeing repeated several times to the extent that several transverse rowsof inclined bristle tufts 5 and 6 are provided (cf. FIG. 5).

With this configuration, the bristle tufts 4 of the first group areconstructed shorter than the bristle tufts 5 and 6 of the second andthird group. The bristle tufts 5 and 6 of the second and third grouphave a greater height in order, as the result of their projection abovethe perpendicularly upstanding bristle tufts 4, to be better able topenetrate into the interproximal area and into the subgingival area ofthe teeth. In the embodiment shown in FIG. 3, the projecting inclinedbristle tufts 5 and 6 in the center of the bristle zone 3 have a heightwhich is greater by 20% to 30%, approximately, than the height of theperpendicular bristle tufts 4 of the first group.

As FIGS. 3 and 5 show, the outer contour, in particular the widestpoints of the bristle zone 3, are defined by the perpendicularlyupstanding bristle tufts 4 of the first group. The inclined bristletufts 5 and 6 of the second and third group extend within thecircumference of the bristle zone 3, which is defined by theperpendicular bristle tufts 4.

The bristle tufts 4 of the first group have in addition a cross-sectionwhich differs from the cross-section of the inclined bristle tufts 5 and6. While the perpendicularly upstanding bristle tufts 4 have anapproximately circular cross-section (cf FIG. 2), the inclined bristletufts 5 and 6 have a slim rectangular cross-section (cf. FIGS. 4 and 5),with the longitudinal sides of this rectangular cross-section extendingparallel to the respective plane in which the bristle tufts 5 and 6 inthe same transverse row are arranged.

1-17. (canceled)
 18. A toothbrush head, comprising: (i) a bristlesupport member defining a plane and containing a longitudinal axis ofthe toothbrush head; (ii) a bristle zone on the bristle support member;(iii) a plurality of bristle tufts arranged in the bristle zone, theplurality comprising: (a) a first group of bristle tufts arrangedsubstantially perpendicular to the plane of the bristle support member;(b) a second group of bristle tufts arranged in transverse rows on thebristle support member, such that all of said bristle tufts are inclinedfrom the outside inwards in a direction transverse to the longitudinalaxis of the toothbrush head towards a first side of the toothbrush head;and (c) a third group of bristle tufts arranged in transverse rows onthe bristle support member, such that all of said bristle tufts areinclined from the outside inwards in a direction transverse to thelongitudinal axis of the toothbrush head towards an opposite second sideof the toothbrush head.
 19. The toothbrush head of claim 18, wherein thebristle tufts in each transverse row of bristle tufts are arranged in acommon plane in which the bristle zone is free from perpendicular andcounter-inclined bristle tufts.
 20. The toothbrush head of claim 18,wherein the bristle tufts in each transverse row of bristle tufts havethe same degree of inclination.
 21. The toothbrush head of claim 18,wherein the bristle tufts in each transverse row are inclined along thelongitudinal axis of the toothbrush head.
 22. The toothbrush head ofclaim 18, wherein the height of the bristle tufts of at least the secondgroup or the third group exceeds the height of the bristle tufts of thefirst group.
 23. The toothbrush head of claim 18, wherein the bristletufts in any one transverse row are different in height.
 24. Thetoothbrush head of claim 18, wherein, for any one transverse row, theheight of the inclined bristle tufts with bristle heads near a center ofthe bristle zone exceeds the height of the inclined bristle tufts withbristle heads near an outer side of the bristle zone.
 25. The toothbrushhead of claim 18, wherein the heads of the inclined bristle tufts in anyone transverse row form an approximately rectilinear contour downwardlysloping towards an outer side of the bristle zone.
 26. The toothbrushhead of claim 18, wherein the heads of the inclined bristle tufts of thesecond and third group define an approximately gable-roof-shaped contourwith a longitudinal axis substantially parallel to the longitudinal axisof the toothbrush head.
 27. The toothbrush head of claim 18, wherein thebristle tufts of the second group are inclined from the second side tothe first side of the toothbrush head and the bristle tufts of the thirdgroup are inclined from the first side to the second side of thetoothbrush head, such that bristle tufts of the second group and,bristle tufts of the first group overlap at least in part along thelongitudinal axis of the toothbrush head.
 28. The toothbrush head ofclaim 18, wherein a base area of the bristle zone is at least as largeas a corresponding working area of the bristle zone.
 29. The toothbrushhead of claim 18, wherein the transverse rows of the second groupalternate with the transverse rows of the third group along thedirection of the longitudinal axis of the toothbrush head.
 30. Thetoothbrush head of claim 18, wherein bristle tufts of the first groupare arranged between the transverse rows of the second group and thetransverse rows of the third group.
 31. The toothbrush head of claim 30,wherein bristle tufts of the first, second, and third groups arealternately arranged along the direction of the longitudinal axis of thetoothbrush head.
 32. The toothbrush head of claim 18, wherein thebristle tufts of the first group have a cross-section that differs fromthe cross-section of the bristle tufts of at least the second or thirdgroup.
 33. The toothbrush head of claim 18, wherein all the bristletufts of the first group have substantially the same cross-sectionalshape.
 34. The toothbrush head of claim 33, wherein the cross-sectionalshape is approximately circular.
 35. The toothbrush head of claims 18,wherein all the bristle tufts of the second and third groups havesubstantially the same cross-sectional shape.
 36. The toothbrush head ofclaim 35, wherein the cross-sectional shape is approximatelyrectangular, and wherein the longitudinal sides of the rectangle extendsubstantially parallel to the longitudinal direction of the transverserow in which the bristle tufts are arranged.
 37. The toothbrush head ofclaim 18, wherein the bristle tufts in the second and third groups areinclined relative to a perpendicular on the bristle support plane at anangle of about 5° to about 45°.
 38. The toothbrush head of claim 37, thebristle tufts in the second and third groups are inclined relative tothe perpendicular on the bristle support plane at an angle of about 10°to about 30°.
 39. The toothbrush head of claim 38, the bristle tufts inthe second and third groups are inclined relative to the perpendicularon the bristle support plane at an angle of about 15° to about 25°.